Reversing roll stand having inlet and outlet guides

ABSTRACT

The invention relates to a reversing roll stand ( 20 ), in particular a Steckel reversing roll stand ( 20 ), with at least one upper backing roll and one lower backing roll ( 2, 4 ) and one respective upper and one respective lower working roll ( 1  and  3 ); and with on the input side and on the output side of the stand respective upper supports ( 8 ) juxtaposed with the upper working roll ( 1 ) and connected to an upper-roll frame via a first actuator ( 6 ). 
     In a deviating position from the upper support ( 8 ) a respective hinge-mounted upper scraper ( 11 ) for the upper working roll ( 1 ) is pivotally movable against the upper working roll ( 1 ) by a respective second actuator ( 12 ) carried on each of the upper supports ( 8 ). 
     The upper supports ( 8 ) are each displaceable in respective lower and upper vertical guides ( 9, 10 ) such that the respective first actuator ( 6 ) can draw it out of the lower vertical guide ( 9 ) and it can be pivoted by a third actuator ( 7 ) outward from the upper working roll ( 1 ). 
     The reversing roll stand ( 20 ) furthermore has on the input side of the stand and the output side of the stand for the lower working roll ( 3 ) respective lower scrapers ( 13 ) adjustably pivotal by respective fourth actuators ( 14 ) against the lower working roll ( 3 ).

The invention relates to a reversing roll stand, in particular a Steckel reversing roll stand, with at least one upper backing roll and one lower backing roll and respective upper and lower working rolls with respective upper and lower guides on the input side of the stand and the output side of the stand.

In the rolling of slab ingots in roughing stands, in reversing operation slab ingots with a thickness of about 250 mm are rolled out to form rough strip with a thickness of about 40 mm. Reversing roll stands of this type have vertically guided upper input and output guides mounted in the stand. During the rolling operation, these upper input guides on the input side of the stand and the upper output guides on the output side of the stand rest on bars fixed between the upper working roll chocks of the reversing roll stand. To change a roll, the upper input and output guides are vertically displaced and release the upper working roll chocks. The support bars are installed in the roll workshop according to the current working roll diameter with a defined distance from the roll surface. Support bars are also installed in the lower working roll chocks. However, they are not in contact with lower guides, there being no contact between support bars and working rolls at the top as well as at the bottom in a reversing roll stand of this type. This is not necessary either, since due to the very large minimum rough strip thickness of about 40 mm, there is no danger that rolling material will reach into the nip between working rolls and support bars.

In finishing stands, the rough strip thicknesses of then about 40 mm are rolled out to a final strip thickness of up to about 1 mm. This is carried out either in a multiple-stand finishing mill in tandem arrangement or in one or two stands in a Steckel arrangement. In Steckel reversing roll stands, the rough strip in reversing operation is rolled out in several roll passes to form the finished product with a final strip thickness of up to about 1 mm. In finishing stands of this type, the upper scrapers usually arranged on the upper input and output guides as well as lower scrapers likewise assigned to the working rolls, which likewise are provided on the input side of the stand as well as on the output side of the stand, are in constant contact with the respectively upper or lower working roll. This is necessary in order to shield the strip surface from roll cooling water or also in order to scrape off any rolling material possibly adhering to the working rolls therefrom. With a change of working roll, these upper and lower scrapers must be pulled back far enough from the respectively assigned working roll that a working roll change is possible.

Based on the different mode of operation and embodiment of roughing stands and finishing stands described above, different stand types or differently equipped stand types are to be used depending on the purpose, which entails a correspondingly complex stockpiling for a factory. There is therefore a need to achieve a simplification here.

The object of the invention is to create a solution that makes it possible to use a reversing roll stand as a roughing stand as well as a finishing stand.

This object is attained according to the invention by a reversing roll stand with the features of claim 1. Advantageous further developments and expedient embodiments of the invention are the subject matter of the dependent subordinate claims.

The invention is a reversing device that meets the requirements for a “roughing stand operation” as well as for a “finishing stand operation.” With the reversing roll stand according to the invention it is possible to press the upper and lower scrapers against the respective working rolls as well as to swing clear the upper and lower guides for a roll change. In particular, Steckel reversing roll stands can be equipped therewith such that when roughing and when finishing they can roll out slab ingots with a thickness of about 250 mm in reversing operation to form a finished product with a final strip thickness of about 1 mm.

According to a first embodiment, the upper support is connected by an actuator and a coupling to the upper backing roll support beam and thus is displaceable relative to the lower vertical guide and can be drawn out of it. The upper supports can thus be moved out of the working space of the working rolls by a simple mechanism and thus release the upper working roll chocks.

Preferably, clamping heads, ball heads and universal joints or simply moveable threaded connections are hereby used as couplings.

Another embodiment of the invention provides that a third actuator that can move the upper support connects this support to the stand or is attached to the backing roll support beam. Thus, depending on the available installation space, an optimal attachment of the upper supports is selected, which in particular in the course of possible maintenance or repair work is easily accessible and easy to assemble or disassemble.

Another embodiment of the invention provides that an upper scraper juxtaposed with the upper working roll, and this scraper can be adjusted or pressed against the working roll by a second actuator. The second actuator ensures that the scraper always has uniform contact with the upper working roll over its entire length. Wear of the scraper edge is then preferably compensated by continuously pressing the scraper against the working roll by the second actuator.

Another embodiment of the invention provides that a lower scraper with a fourth actuator is arranged such that the scraper is pressed against the working roll or is moved away from the working roll by the actuator and thus can be swung clear of the installation area or removal area of the working rolls. Thus the installation space for the working rolls is freely accessible, without major installation work on the arranged scrapers being necessary. Both scrapers now lie outside the outer extents of the working roll chocks and are clear of them during a working roll change.

The arrangement of the scrapers can be provided in a special embodiment of the invention such that swinging clear the scrapers can be carried out upward and/or downward. A flexible adjustment to the existing space conditions is thus possible.

The embodiment of the invention described above is further benefitted in that the upper and lower scraper is cardanically mounted. With this type of mounting, swinging clear in any direction is rendered possible

Thus in a further embodiment of the invention it is shown that the upper and lower scraper can be pivoted out from the working space between the working roll chocks.

In a further embodiment of the invention the actuators are lift cylinders in the form of a hydraulic cylinder or pneumatic cylinder or in the form of a driven spindle. It is therefore possible according to the connections present where installed, such as, for example, hydraulic connections, pneumatic connections or electric connections or a combination of all three according to the structural conditions, to select an optimal actuator that takes up as little of the installation space of the working rolls as possible and provides an optimal adjustment mechanism.

In a further embodiment of the invention the upper support on the reversing roll stand is pivoted on connecting elements on which one end of a lift cylinder with clamping head and one end of a second pneumatic cylinder acts. Depending on the construction of the connections of the connecting element, for example, the arrangement of different bores, a corresponding angular adjustment of the lift cylinders with respect to one another is possible and thus can be adjusted to the space conditions.

The invention is described in more detail below by way of example based on the drawing. Therein:

FIG. 1 is a schematic section through part of a Steckel reversing roll stand, the left side showing the position during rolling and the right side the position during exchange of working rolls,

FIG. 2 is a diagrammatic view in the rolling direction of part of a Steckel reversing roll stand, and

FIG. 3 are diagrammatic top views showing on the left part of an upper support and on the right part of a lower guide in their operational position when rolling.

As shown on the left of FIG. 1, when rolling, an upper working roll 1 and an upper backing roll 2 as well as a lower working roll 3 and a lower backing roll 4 are in contact with one another. In the roll position shown only on the left, upper scrapers 11 engage the upper working roll 1 and lower 13 engage the lower working roll 3. The upper scrapers 11 are mounted on respective upper supports 8 connected by respective actuators 6, for example, a lift cylinder with clamping head, to an upper-backing roll support beam 5. Each upper support 8 is guided in respective lower vertical guides 9 and respective upper vertical guides 10 in the Steckel reversing roll stand shown at 20. The upper scrapers 11 are pivotal on the upper support 8, in particular by means of universal joints. Second actuators 12, for example pneumatic cylinders carried on the upper supports 8, can pivot the upper scrapers 11 against the respective upper working roll 1. A rotation axis 16 about which the upper scraper 11 can be rotated is positioned such that the edge of the upper scraper 11 can be brought into contact with the upper working roll 1 over the entire length of the scraper 11. Wear occurring on the longitudinal edges of the upper scrapers 11 is compensated for by continuous adjustment action of the respective second actuators 12. The first actuator 6 with clamping head, which is pivotal on the upper backing roll support beam 5, is pivoted on the upper end of the upper support 8 and when rolling as shown on the left in FIG. 1 is locked such that it rigidly connects the beam 5 and the upper support 8. All necessary or resulting changes in the height of the roll nip 15 are followed when rolling by the locked upper supports 8 via the upper backing roll support beam 5. The strokes of the first actuators 6 are adjusted according to the current working-roll diameters and backing roll diameters in a position-regulated manner and locked by means of the clamping head integrated into the lift cylinder 6.

The lower scrapers 13 are also pivotal, preferably cardanically, about axes or rotation points 17 in the area of the lower working roll 3 on the reversing roll stand 20. With the aid of fourth actuators 14 (not shown in detail), the lower scrapers 13, preferably located ahead of a support beam, are pressed against the lower working roll 3 in a manner analogous to the upper scrapers 11.

As can be seen in particular from FIGS. 2 and 3, two fourth actuators 14 are assigned to each lower scraper 13, positioned symmetrically to the lower scraper 13 and on the one hand are supported on the lower scraper 13 and on the other hand are supported on the reversing roll stand 20 or elements arranged thereon. Likewise, two symmetrically arranged lift cylinders 6 are assigned to each upper support 8 and one lower vertical guide 9 and one upper vertical guide 10, which interact with corresponding counter-elements carried on the reversing roll stand 20, are provided at each end of each upper support 8.

Each upper support 8 is pivotable about an axis 21 on a connecting element 19 attached to the lift cylinder 6 and a third actuator 7 has one end also pivoted at an axis 22 on the connecting element 19 and another end pivotable about an axis 23 to part of the respective upper support 8 at a location spaced from the connecting part 19. A plurality of the third actuators 7 is thus assigned to each upper support 8 like the number of first actuators 6. In the illustrated embodiment there are two hydraulic cylinders.

In order to now move the lower scrapers 13 and the upper scrapers 11 into the roll-change setting or position shown on the right in FIG. 1, which position makes it possible to change the upper and lower working rolls 1 and 3, the upper supports 8 on the input and on the output side of the stand are raised by the respective upper backing roll support beam 5 together with the upper backing roll 2 so far that the upper working roll 1 and the upper backing roll 2 move out of contact with one another, as shown on the right in FIG. 1. Subsequently, the clamping heads of the lift cylinder 6 are released and the upper supports 8 are lifted by the first actuators 6 so far that these upper supports 8 leave the lower vertical guides 9 and can be pivoted about the axes 24 while still guided in the upper vertical guides 10. This pivoting movement is now effected by the third actuators 7, which to this end retract their piston rods into their pistons and shorten, so that the upper supports 8, as shown in the right in FIG. 1, pivot outward and thus release the region of the upper working roll 1 for a change of the upper working roll 1. Subsequently, the lower scrapers 13 are pivoted by the fourth actuators 14 into the open position shown in the right in FIG. 1. The upper scrapers 11 as well as the lower scrapers 13 pivot outward away from the working rolls 1 and 2. After the lower scrapers 13 have reached their roll-change position, the lower backing roll 4 is lowered so far that the lower working roll 3 rests pm working roll extension rails 18 in the reversing roll stand 20. With further lowering of the lower backing roll 4, the lower working roll 3 and the lower backing roll 4 then also go out of contact with each other so that the lower working roll 3 can now also be replaced.

In roll-change position shown on the right in FIG. 1, the upper scrapers 11 as well as the lower scrapers 13 are so far outside the outer extents of the working roll parts or working roll chocks that they can be removed to change and expose the working roll. 

1. A reversing Steckel reversing roll stand, with at least one upper backing roll and one lower backing roll and one respective upper and one respective lower working roll; and with on the input side and on the output side of the stand respective upper supports juxtaposed with the upper working roll and connected to an upper region of an upper-roll frame via a first actuator; and that from the upper support a respective hinge-mounted upper scraper for the upper working roll is pivotally movable in a deviating direction against the upper working roll by a respective second actuator carried on each of the upper supports; and the upper supports are each displaceable in respective lower and upper vertical guides such that the respective first actuator can draw it out of the lower vertical guide and it can be pivoted by a third actuator outward from the upper working roll; and the reversing roll stand furthermore has on the input side of the stand and the output side of the stand for the lower working roll respective lower scrapers adjustably pivotal by respective fourth actuators against the lower working roll.
 2. The reversing roll stand according to claim 1, wherein the upper support is connected with the first actuator via a coupling to the upper backing roll support beam and can be pulled out of the lower vertical drive.
 3. The reversing roll stand according to claim 2, wherein the coupling is a clamping head, ball head, universal joint or a simple mechanical connection.
 4. The reversing roll stand according to claim 1, wherein the third actuator is mounted on the rolls stand or on the backing roll support beam and/or on the upper support.
 5. The reversing roll stand according to claim 1, wherein the upper scrapers are juxtaposed with the upper working roll, and the scrapers can be adjusted and pressed against the working roll via the respective second actuators.
 6. The reversing roll stand according to claim 1, wherein each lower scraper with the respective fourth actuator is arranged such that the actuator presses the scraper against the working roll or moves it away from the working roll and swings it clear of the installation area or removal area of the working rolls.
 7. The reversing roll stand according to claim 6, wherein the swinging clear can be upward or downward.
 8. The reversing roll stand according to claim 1, wherein the upper and lower scrapers are cardanically mounted.
 9. The reversing roll stand according to claim 1, wherein the upper and lower scrapers are arranged to be swung out from between the working roll chocks.
 10. The reversing roll stand (20) according to claim 1, that wherein the actuators are lift cylinders in the form of a hydraulic cylinder or pneumatic cylinder or in the form of a driven spindle.
 11. The reversing roll stand according to claim 1, wherein the upper supports are pivotal connecting elements, on each of which one end of a respective one of the lift cylinders with clamping head and one end of a respective one of the second hydraulic cylinders acts. 